That can have many causes. - Have you centered your enitity origins?- Is one of the walls that are seperating the "inside" of your map from the void a func_detail?- Have you checked alt + p to see if there are any problems?
You can post the file here or give it to me on steam. I can take a look at it if you want.
Just upload it to mega or something, click on the little globe under profile image to get to my steam profile.
nah
Post the full link plus key at the end, like this https://mega.co.nz/#!3IACSSaY!rNrBn8mlQqd9am2bs6GP9yrkCI_C1rUQQmRrwPO9FVw